How Is Barometric Pressure Measured and Why?

gate ab in fig p251 is 12 m long and 08 m into the paper neglecting atmospheric pressure effects compute the force f on the gate and its center of pressure position x 40503

Gate A B in Fig. P2.51 is 1.2 m long and 0.8 m into the paper. Neglecting atmospheric pressure, compute the force F on the gate and its center-of-pressure position X | Numerade